1. Field of the Invention
The present invention relates to an alkaline earth metal silicate-based phosphor and a white light-emitting device including the same. More particularly, the present invention relates to an alkaline earth metal silicate-based phosphor having a broad excitation wavelength range, an emission spectrum over a broad wavelength range, and good emission efficiency, and a white light-emitting device including the same.
2. Description of the Related Art
Semiconductor-based white light-emitting devices (“white LEDs”) have advantages of a longer lifetime, a smaller size, and a lower driving voltage than incandescent lamps, and thus, have been considered as potential substitutes for conventional light sources in all aspects of the illumination field, including fluorescent lamps, backlights of liquid crystal displays, and the like.
White LEDs can produce white light by combining red, green, and blue LEDs emitting light of the three primary colors, red, green, and blue, exciting a yellow phosphor using a blue LED as a light source, or exciting red, green, and blue phosphors using a UV LED as a light source.
In the manufacture of white LEDs as described above, generally, K5Eu2.5(WO4)6.25, La2O2S:Eu, or the like can be used as a red phosphor, (Ba,Sr)2SiO4:Eu or the like can be used as a green phosphor, and Sr5(PO4)3Cl:Eu or the like can be used as a blue phosphor.
White LEDs producing white light by exciting red, green, and blue phosphors using a UV LED as a light source can be used under high current and can produce good white light, and thus, have attracted the most research interest. White LEDs producing white light by exciting a green phosphor, e.g., ZnS:Cu,Al, BaMgAl10O17:Eu,Mn (e.g., from Mitsubishi Chemical), and the like, using a UV-LED as a light source have been applied to cathode ray tubes (“CRTs”), illuminators, and the like. However, conventional phosphors exhibit low emission efficiency due to poor solidification, and have a narrow emission peak wavelength range, and thus, it is difficult to produce a spectrum of light similar to natural light.